Brussels, July 9 (RHC)-- NATO says it is "ready to stay" in Afghanistan, reiterating a pledge on funding for local security forces. NATO Secretary General Jens Stoltenberg said Saturday, highlighting the funding pledge through 2020, that military forces would remain in Afghanistan, without saying when that military engagement in Afghanistan might end.

Under the leadership of the United States, the 28-nation Western military alliance invaded Afghanistan in 2001, starting a war that has killed thousands and cost tens of billions of dollars. The military engagement was meant to obliterate the Taliban, but the militant group has managed to gain more footholds across the country over the past years, and local security forces still struggle to contain the group and other militants, including al-Qaeda and the Takfiri Daesh terrorists.

Stoltenberg said NATO will maintain troops in Afghanistan through 2017 under its train and advise Resolute Support Mission. He did not provide numbers but said the overall NATO force in Afghanistan would be "around the same" as now. Resolute Support currently has about 13,000 troops in Afghanistan.

Washington, the main provider of troops and funding to NATO in Afghanistan, has also backed down on its previous pledges to reduce the number of troops in the country, arguing that Kabul has been quite slow in reforming its military, which the United States claims is gripped by corruption and human rights issues.

U.S. President Barack Obama had previously vowed to slash troop numbers from the current 9,800 to 5,500 by the end of this year. However, he announced on July 6 that the process will draw down and the U.S. would keep 8,400 U.S. troops in Afghanistan.